//Copyright (C) 2006 Richard J. Northedge
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

//This file is based on the PTBMentionFinder.java source file found in the
//original java implementation of OpenNLP.  That source file contains the following header:

//Copyright (C) 2003 Thomas Morton
//
//This library is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public
//License as published by the Free Software Foundation; either
//version 2.1 of the License, or (at your option) any later version.
//
//This library is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public
//License along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

using System;

namespace OpenNLP.Tools.Coreference.Mention
{
	/// <summary>
    /// Finds mentions from Penn Treebank style parses.
    /// </summary>
	public sealed class PennTreebankMentionFinder : AbstractMentionFinder
	{
		private static PennTreebankMentionFinder mInstance = null;
		
		/// <summary>
        /// Creates a new mention finder with the specified head finder.
        /// </summary>
        /// <param name="headFinder">
        /// The head finder.
		/// </param>
		private PennTreebankMentionFinder(IHeadFinder headFinder)
		{
			PrenominalNamedEntitiesCollection = false;
			CoordinatedNounPhrasesCollection = true;
			HeadFinder = headFinder;
		}
		
		public static PennTreebankMentionFinder GetInstance(IHeadFinder headFinder)
		{
			if (mInstance == null)
			{
				mInstance = new PennTreebankMentionFinder(headFinder);
			}
			else if (mInstance.HeadFinder != headFinder)
			{
				mInstance = new PennTreebankMentionFinder(headFinder);
			}
			return mInstance;
		}
		
		/*
		private boolean isTraceNp(Parse np){
		List sc = np.getSyntacticChildren();
		return (sc.size() == 0);
		}
		
		protected List getNounPhrases(Parse p) {
		List nps = new ArrayList(p.getNounPhrases());
		for (int npi = 0; npi < nps.size(); npi++) {
		Parse np = (Parse) nps.get(npi);
		if (!isTraceNp(np)) {
		if (np.getSyntacticChildren().size()!=0) {
		List snps = np.getNounPhrases();
		for (int snpi=0,snpl=snps.size();snpi<snpl;snpi++) {
		Parse snp = (Parse) snps.get(snpi);
		if (!snp.isParentNAC() && !isTraceNp(snp)) {
		nps.add(snp);
		}
		}
		}
		}
		else {
		nps.remove(npi);
		npi--;
		}
		}
		return (nps);
		}
		*/
		
		/// <summary>Moves entity ids assigned to basal nps and possesives to their
		/// maximaly containing np.  Also assign head information of basal
		/// noun phase to the maximally containing np.
		/// </summary>
		/// <deprecated> No on uses this any more.
		/// 
		/// private void propigateEntityIds(Map headMap) {
		/// for (Iterator ki = headMap.keySet().iterator(); ki.hasNext();) {
		/// Parse np = (Parse) ki.next();
		/// if (isBasalNounPhrase(np) || isPossessive(np)) {
		/// int ei = np.getEntityId();
		/// if (ei != -1) {
		/// Parse curHead = np;
		/// Parse newHead = null;
		/// while ((newHead = (Parse) headMap.get(curHead)) != null) {
		/// curHead.removeEntityId();
		/// curHead = newHead;
		/// }
		/// curHead.setEntityId(ei);
		/// curHead.setProperty("head", np.getSpan().toString());
		/// }
		/// }
		/// }
		/// }
		/// </deprecated>
	}
}